Computer systems typically comprise a combination of computer programs and hardware, such as semiconductors, transistors, chips, circuit boards, storage devices, and processors. The computer programs are stored in the storage devices and are executed by the processors.
Computers are often connected via networks, such as in cloud computing or client/server models. In one use of such models, programs (also called applications or applets) are downloaded from one computer, called a server, across a network to another computer, called a client, where the programs execute.